Living room lamps, table lamps or pocket lamps of conventional construction are equipped with incandescent bulbs which have the drawback that at relatively high current demands, only a relatively small part of the energy consumed is used to produce the light. Indeed, xenon lamps of higher light output or energy-saving lamps with a cost saving are possibly used as house or table lamps but even here, further optimization is desirable.
For pocket lamps or flashlights it is known to dispose the incandescent bulbs generally in the region of the focal point of a reflector of a concave configuration. Usually such reflector is in the form of a so-called parabolic mirror which enhances the light output of the pocket lamp. An incandescent filament of a pocket lamp bulb radiates to all sides in the switched-on state of the lamp so that by reflection, the light which is radiated away from the front opening in the lamp head is redirected by one or more reflections into a substantially longitudinal axial direction and thus is useable. In accordance with the state of the art, there are also pocket lamps known in which a reflector is shiftable in the longitudinal axial direction to produce differently radiating light cones. This shiftability can be achieved either via a longitudinal axially-extending guide, through a translatory shifting or through a rotary movement in which the reflector is shiftable by rotation depending upon a threading pitch. In a corresponding manner the incandescent lamp within a reflector which is rigid with the lamp head can be moved longitudinally axially via a slider or the like which, however, is of expensive construction. The change in the light bundle configuration which is radiated outwardly can, depending upon the reflection of the beam from the incandescent lamp on the inner surface of the reflector, be in the form of a substantially parallel light beam output when the incandescent lamp or its incandescent filament is located at the focal point of the hollow mirror.
From U.S. Pat. No. 4,783,735 a flashlight lamp is known which has a reflector and two incandescent lamps, light-emitting diodes or laser diodes located at different positions by means of which the shadow effect which can arise with only one incandescent lamp, can be avoided. The reflector to achieve this purpose and the transparent cover through which the light emerges are, however, of complex construction since the emitted radiation is perpendicular to the longitudinal axis of the pocket lamp and as a result the lamp can be manipulated only with difficulty.
A flashlight is described in EP 0 921 345 which has, apart from a two-filament incandescent lamp, two light-emitting diodes at the lamp outer shell which achieves the object of enabling the turned-off lamp to be readily recognizable even in the dark if the light-emitting diode has to be turned on. In the meantime flashlights have also become known in which a high light intensity diode serves as the single light source.